WASHINGTON (CNN) -- National security adviser Condoleezza Rice made history on Tuesday with her nomination as the country's next secretary of state.

A modern-day renaissance woman who traded the stately halls of Stanford University for the political swirl of Washington, Rice became one of President Bush's most trusted wartime advisers.

Rice, who turned 50 on Sunday, was be the first black woman, and only the second woman ever, tapped to be the nation's top diplomat. As national security adviser for the past four years, she has become one of Bush's closest confidantes and primary counselors as the nation waged a war on terror that was unimaginable when the administration took office in 2001.

She was also a staunch proponent of Bush's decision to invade Iraq -- a policy she has robustly defended in the face of a violent insurgency that has raised questions about how well the administration prepared for the post-war period.

If confirmed by the Senate, Rice would take the diplomatic reins as the United States tries to repair international relationships strained by Bush's Iraq policy, which she helped craft inside the White House.

Rice's association with Bush goes back to the 2000 presidential campaign, when she worked as an adviser on national security issues after stepping down from six years as Stanford University's provost, or chief academic and budget officer.

Appointed national security adviser after Bush was elected, she moved to Washington and became the focus of much media attention, due as much to her unusual background and myriad accomplishments as to the power of her post.

Born in segregated Alabama in 1954, Rice entered college at 15 and by 26 had earned a Ph.D. in international affairs from the University of Denver. While there, one of her mentors was professor Joseph Korbel -- the father of Madeleine Albright, the only other woman to hold the portfolio of secretary of state.

In 1981, Rice moved to California to take up a political science professorship at Stanford, where she built a reputation as an expert on the Soviet Union. She later served as a National Security Council staffer during the administration of Bush's father, when communism was crumbling in Europe.

Rice, who speaks four languages, is also an accomplished figure skater and classically trained pianist. In April 2002, she took the stage at Washington's Constitution Hall to perform with acclaimed cellist Yo-Yo Ma.

As the crest of public attention grew, Rice, despite her lack of elected political experience, was even mentioned as a possible vice presidential running mate for Bush in 2004 in place of Dick Cheney, with at least one Web site devoted to the idea.

However, in the past year, opinions of Rice have become more divided, as difficulties increased in Iraq and the commission investigating the terrorist attacks of September 11, 2001, probed what she and other administration officials did -- and did not do -- in the months leading up to the worst-ever terror attack on U.S. soil.

The Bush administration, citing executive privilege, initially refused to let Rice testify in public hearings before the commission. But the White House eventually relented after her former deputy, Richard Clarke, went public with charges that Rice did not take the threat of al Qaeda seriously before the attacks.

In April, Rice defended the administration's record for nearly three hours, insisting that there had been "intense" efforts against terrorism during the summer of 2001 but that there was "no silver bullet" that could have prevented the attacks. (Full story)

"Had we thought that there was an attack coming in Washington or New York, we would have moved heaven and earth to try to stop it," she said. "And I know that there was no single thing that might have prevented that attack."

But Rice was pressed repeatedly about an intelligence memo presented to Bush one month before the attacks, a document that referred to al Qaeda, Osama bin Laden and possible hijackings.

Asked by Democratic commissioner Richard Ben-Veniste, a former Watergate prosecutor who has read the memo, to recall the title, Rice said: "I believe the title was 'Bin Laden Determined to Attack Inside the United States.' "

On Iraq, Rice has been steadfast in her position that Iraqi dictator Saddam Hussein posed a threat that had to be dealt with, despite the fact that no weapons of mass destruction have been found since his regime was toppled in April 2003. (Full story)

"This was a dictator who had actually used weapons of mass destruction against his neighbors, against his own people," she told CNN in September. "This was a dictator who was shooting at our aircraft practically every day in the no-fly zone as we tried to enforce the Security Council resolutions. And this was a dictator who was a destabilizing force in the world's most unstable region."